Fluid valve structures

ABSTRACT

A fluid valve structure is provided having spaced first and second inlet sections connected to a source of pressure fluid and a plurality of side by side valve sections between said inlet sections, each having inlet, work and tank chambers intersected by a passage open at opposite ends to a control chamber and a tank chamber at a common pressure, a valve spool movable in said passage and having both ends at a common pressure and grooves adapted selectively to connect the work chamber to the inlet or tank chamber, a lever in the control chamber removably engaging one end of the spool and rotatable about a shaft transverse to the spool axis, and an external handle means operatively engaging the shaft to rotate the lever to move the spool axially in the passage, all of the spool, lever and shaft being fully enclosed with a valve housing in all operative positions.

This application is a continuation of my copending application Ser. No.820,262, filed Jan. 17, 1986, now U.S. Pat. No. 4,709,724.

This invention relates to fluid valve structures and particularly tofluid valves for multivalve assemblies for mobile equipment such asmotor graders and the like.

Fluid valve structures have been used for many years and have taken agreat variety of configurations and operating characteristics. A verycommon and universally used fluid valve is the axially movable spoolvalve which may be assembled in side by side relationship with likeother valves to form a bank of valves capable of operating amultiplicity of fluid consumers. Such valves have been used for manyyears. They have, however, many defects and limitations both in uses andoperation. They are subject to considerable frictional forces due to theseals through which at ends of the spool pass. The exposed ends aresubject to wear from dirt which carries into the seal and damages boththe seal and spool. This wear causes the seals to fail and leak.

An additional problem with the conventional method of moving the spoolby the axially applied manual forces is that these forces can be verylarge when the spool reaches its stop position. These large forces candistort the spool causing it to bind in its close fit bore or damage therelatively fragile end stop parts.

The present invention utilizes a rotary input to the fluid chamber and alever from this rotary input to the spool to move the spool axially.This arrangement solves all of the previously cited problems byproviding a valve structure which reduces frictional forces due to sealsto a minimum and eliminates the movement of any element from a hydraulic(wet) chamber to a dry area as the spool is stroked from position toposition which excludes external dirt from any part of the valve spool.In addition, it provides rugged end stops on the housing to limit spoolmotion without transmitting any end stop forces through the spool or thelever arrangement.

This rotary input arrangement allows disassembly of the spool from thevalve section without removing the section from the valve bank similarto conventional spools which have thru axial seals. In addition, itallows the input arm to float axially so that it cannot cause the spoolto bind as it is stroked. Other rotary input arrangements have been usedfor mobile valves, but they do not solve the problems of high frictionalforces, exclusion of dirt, and large manual forces being transmitteddirectly through the spool to limit the spool motion; because the rotaryinput has been accomplished outside of the fluid cavity.

In the valve according to the invention one can also provide a uniquearrangement of spool and land timing so that flow forces are minimizedby the design of spool flow slots while separate spool venting slotsallow both work ports to vent to the tank when the spool is in neutral,insuring the proper seating of the pilot operated check valves. Thisarrangement also provides system pressure to open the load holding checkvalves after the spool moves to shut off the spool vent slots to tankconnection and the spool flow slots direct system pressure to either oneof the two work ports.

The valve may also provide a detented fourth position float in which thespool opens both work ports to the tank and directs pressure to dualpistons to open both load holding checks when the spool is moved to afloat position.

A fourth feature of this valve is that the detent used to hold the spoolin the float position does not cause any frictional drag on the spooluntil the spool enters the float position.

A final feature of this valve is that an external pressure passageparallel the internal valve pressure passage may be provided connectinga first inlet section to a second inlet section at opposite ends of amulti-valve bank. This parallel passage provides inlet fluid pressure atboth ends of the valve bank to minimize pressure losses in providingfluid flow to the intermediate valve sections.

We provide a fluid valve structure comprising a first inlet sectionseparately connected to a source of pressure fluid and to a reservoir ortank, a second inlet section connected to a source of pressure from thefirst inlet section, a plurality of side by side valve sections betweensaid inlet and second inlet sections, each valve section having ahousing with a pressure source chamber, two work chambers and a tankchamber, intersected by a passage open at both ends to the tank chamber,a valve spool having both ends in the tank chamber and being movable insaid passage, lever means in said tank chamber, said lever beingrotatable with a shaft located transverse to and spaced from the axis ofthe spool valve, handle means to rotate the shaft whereby the valvespool moves axially in the passage, parallel passage means connectingsaid first inlet section and said second inlet section and priorityvalve means in said first inlet section dividing pressure fluid enteringthe first inlet section primarily to an auxiliary port for steering andsecondarily to the first inlet section pressure chamber and through theexternal parallel passage to the second inlet section pressure chamber.

Preferably the lever means is removably fixed in a shaft extendingthrough the housing spaced from the valve spool in a plane transverse toits axis, both ends of said shaft extending out of the housing through aseal and at least one end connected to an operating lever moving betweenfixed end stops on the housing. The spool is preferably removable fromthe passage at that end opposite the lever means after removal of thelever means. Means are preferably provided to vent the work ports to thetank when the spool is centered in neutral position. Preferably meansare provided in the work section whereby system pressure opens the loadholding checks after the spool moves to close the work port to tankconnection. A detented fourth position float (both work ports wide opento tank) may be provided at which position the spool directs pressure todual pistons, opening both load holding checks when the spool is intothis detented fourth float position. When not in this detented fourthfloat position the metering and load holding checks are opened by thetwo pistons operating as a single piston.

In the foregoing general description I have set out certain purposes,objects and advantages of my invention. Other purposes, objects andadvantages of the invention will, however, be apparent from aconsideration of the following description and the accompanying drawingsin which

FIG. 1 is a top plan view of a valve bank assembly according to theinvention;

FIG. 2 is a side elevational view of the valve bank of FIG. 1;

FIG. 3 is an end elevational view from the first inlet section end ofthe valve bank of FIG. 1;

FIG. 4 is an end elevational view from the second inlet end of the valvebank of FIG. 1;

FIG. 5 is a section through a first inlet section of this invention;

FIG. 6 is a section through a work section not vented to tank inneutral;

FIG. 7 is a section through a work section vented to tank in neturalwith load holding checks;

FIG. 8 is a section through a work section vented to tank at neutralwith load holding checks and detented position float;

FIG. 9 is an elevation, partly in section of the second inlet section;and

FIG. 10 is a section showing the input lever.

Referring to the drawings there is illustrated a valve bank according tothis invention made up of an inlet section 10, a second inlet section 11and a plurality of individual intermediate valve work sections 12, whichmay take any of the forms illustrated in FIGS. 6 through 9, dependingupon their desired function.

The first inlet section 10 is provided with an inlet port 20 which isconnected to a source of pressure fluid such as a pump (not shown) andan outlet port 21 connected to a reservoir or tank (not shown). Thefirst inlet section is also provided with a secondary (nonpriority)pressure port 22 threaded to receive a fitting for a 1/2 inch O.D. tubeconnected to a like port, described hereafter, on the second inletsection 11. The first inlet section has an inlet passage 23 connected tothe inlet port which intersects priority chamber 24 (primary flow);nonpriority chamber 25 (secondary flow), connected to port 22; and tankchamber 26 connected to tank passage 27 and outlet port 21. A pressurecontrol spool 28 is slidably mounted in passage 23 to extend across andclose chambers 25 and 26 from passage 23 and to extend into chamber 24.Spool 28 has an inner axial passage 29 having a shoulder 30 intermediateits ends against which an orifice member 31 is pressed by spring 32. Thevalve spool 28 is urged by spring 32 to close off flow from passage 23to passage 25 (through radial holes 33). As pressure builds in chamber23 the spool is moved leftward (viewing FIG. 5) against the spring forceto allow secondary flow from passage 23 to passage 25 through holes 33.Chamber 25 feeds fluid to both ends of the valve bank through passage25a at the first inlet end and port 22 to port 90 in the second inletsection so that even at high flow rates sufficient pressure ismaintained in those valve section remotes from the first inlet sectionand adjacent the second inlet section.

The intermediate sections 12 may take one of several forms, asillustrated in FIGS. 6 through 8. In FIG. 6, there is illustrated a fourway valve according to the invention. This valve has a housing 35 havinga passage 36 extending out of one end of the housing through a tankchamber 37 in which centering springs are located. Passage 36 extendsthrough two spaced work chambers 38 and 39, a pressure chamber 40between the work chambers, a pair of tank chambers 41 and 42 on oppositesides of the work chambers and a control chamber 44 opening into tankchamber 41. The work chambers 38 and 39 are connected to work ports 38aand 39a. Pressure chamber 40 is connected through an inlet port 40a withthe pressure passage 25a of the inlet section. The tank chambers 41 and42 connect with tank passage 43 extending transversely of housing 35 andconnecting with outlet passage 27 of the first inlet section. A valvespool 45 is movable axially in passage 36. One end of spool 45 islocated in control chamber 44 and is provided with a socket 46 adaptedto receive a ball connection 47 on one end of a drive lever 48. Theother end of drive lever 48 is threaded in an opening 49 in shaft 50journaled in housing 35. An opening 51 is provided in housing 35 inalignment with the axis of drive lever 48 when spool 45 is in theneutral position, which opening is normally closed by threaded plug 52.If it is desired to remove drive lever 48 from shaft 50, plug 52 isremoved through opening 51. This leaves the end of spool 45 free fromthe drive. One end of shaft 50 passes through a bearing and seal in thewall of housing 35 and is connected to an external operating lever 53.The opposite the opposite end of shaft 50 passes through a bearing andseal in the opposite wall of housing 35 so that no net axial force canbe applied on shaft 50 by hydraulic pressure existing in control chamber44.

The opposite end of spool 45 is connected with a conventional centeringmechanism made up of a spring 54 between spring guides 55 and 56 in tankchamber 37. Centering chamber 37 is closed by plug 57 of conventionalform.

In operation, movement of lever 48 counterclockwise (viewing FIG. 6)causes spool 45 to move to the left. This movement connects work chamber38 with tank chamber 41 through valley (slot) 45a on spool 45. In turn,work chamber 39 is connected with pressure chamber 40 through valley(slot) 45b on spool 45. Clockwise movement of lever 48 reverses the workchamber connections.

In FIG. 7 there is illustrated a modification of the valve of FIG. 6which is vented to tank in netural and which incorporates load holdingcheck valves. Like parts are identified by like numbers with a primesign. In this configuration the spool 45' is provided with slots 60,which in the neutral (center) position, as illustrated in FIG. 7,connect work chambers 38' and 39' with the adjacent exhaust chambers 41'and 42' respectively. Each of work chambers 38' and 39' are separatedfrom their respective work ports 38a' and 39a' by a load holding check61 in cartridge 62 inserted in passages 38b and 39b between workchambers 38' and 39' and work ports 38a' and 39a'. A pilot piston 65moving in passage 66 between work chamber 38' and 39' moves under workport pressure to open one or the other of load holding checks 61 afterthe spool mvoes to shut off the work port to tank connection. The spoolarrangement is such that in the neutral position the work chambers areboth connected to adjacent tank chambers and, on movement in eitherdirection, all chambers are first isolated and then one work chamber ispressurized which actuates pilot piston 61 to open the load holdingcheck to the other work chamber that is to be exhausted to tank.

In FIG. 8, there is illustrated a modification of the valve of FIG. 7incorporating a detented fourth position float. Like parts areidentified by like numbers with a double prime sign. In thisconfiguration, in addition to the inclusion of slots 60" to function asin FIG. 7, there is another chamber 70 in housing 35" between pressurechamber 40" and work chamber 39". A pair of pilot pistons 71 and 72 areoperatively movable in passage 66" between work chambers 38" and 39" andchamber 70 intersects passage 66" between these pistons 71 and 72. Theend of spool 45" is provided with detent balls 73 held in openings 74 inball carrier 75 by a conical piston 76 loaded by spring 77 against pin6. The balls are not forced into contact with any part of the housinguntil spool 45" is moved to the right, viewing FIG. 8 to contact land 78in advance of detent 79. When balls 73 contact land 78 they meet theirfirst resistance and then enter detent 79 where the valve is held in thefloat position. In this position pressure fluid from chamber 40" enterschamber 70 to act on pilot pistons 71 and 72 to urge them apart intocontact with load checks 61" to open them into chambers 38" and 39"which are in turn connected with tank chamber 41" and 42" through valley80 and 81 on spool 45". This structure is unique in providing dualpistons to open both load holding checks when the spool is in the floatfor fourth position and in the fact that the detent arrangement does notcause any frictional drag on the spool until immediately prior to itsentering the detent. In positions of the spool 45" off of center but notinto the fourth float position the load holding checks 61" are operatedby 71 and 72 acting as a single piston as in FIG. 7.

The second inlet section 11 provides a connection to the pressurechamber 40 and a termination to tank passage 43 of the preceding workingsection 12 in the valve bank. In addition it is provided with an inletpassage 90 (connected to passage 40 (40'-40"). Inlet passage 90 isexternally connected with the nonpriority passage 25 of the first inletsection by an appropriate piping connection (not shown), such as a 1/2inch tube or the like, which is parallel to the internal passage 40.

In the above description and accompanying drawings, I have illustrated avalve bank made up of individual bolted together housing sections, eachwith a valve spool, however it could be made up of single housings withtwo or more spools and one or two inlets in one or more housings.

In the foregoing specification I have set out certain preferredpractices and embodiments of this invention, however, it will beunderstood that this invention may be otherwise embodied within thescope of the following claims.

I claim:
 1. A fluid valve structure comprising a first inlet sectionseparately connected to a source of pressure fluid and to a reservoir, asecond inlet section spaced from said first inlet section, a pluralityof side by side valve sections between said first inlet and second inletsections each having a housing with at least one inlet chamber, a workchamber and a tank chamber intersected by a passage open at oppositeends to a control chamber intersected by a passage open at opposite endsto a control chamber and a tank chamber at a common pressure, a valvespool having both ends in said chamber at a common pressure and beingmovable in said passage, said spool having spaced grooves adapted in oneposition to connect said work chamber to the inlet chamber and in asecond position to connect the work chamber with a tank chamber, levermeans in said control chamber engaging one end of the valve spool, saidlever means being rotatable about a shaft whose axis is transverse toand spaced from the axis of spool valve, seals and bearings in saidhousing through which both ends of said shaft pass to the outside of thevalve housing, handle means external of the housing acting on the shaftmeans to rotate the lever means whereby the valve spool moves axially inthe passage, said shaft, lever means and valve spool being fullyenclosed within the valve housing in all operative positions, said levermeans being threadingly removably engaged in said shaft, stop means onthe lever means fixing the operative position of the lever means in saidshaft, and wherein said housing is provided with an opening and closuretherefor through which the lever means may be removed from the shaft andfrom the housing leaving the valve spool free in said passage.
 2. Afluid valve structure as claimed in claim 1 wherein the shaft and handlemeans are axially located by the engagement of the lever means in thespool.
 3. A fluid valve structure as claimed in claim 1 wherein eachspool has a centering mechanism for automatically centering the spoolwhen the lever means is not actuated.
 4. A fluid valve structure asclaimed in claim 1 or 2 or 3 wherein at least one valve section has aspool with slots which connect each work chamber with an adjacentexhaust chamber when the spool is centered in its passage.
 5. A fluidvalve structure as claimed in claim 4 wherein each work chamber isprovided with a load holding check and a passage connecting said workchambers carrying a pilot piston operative on pressure from one workchamber to move the pilot piston to open the load check in the otherwork chamber.
 6. A fluid valve structure as claimed in claim 5 whereinthe valve slots are arranged for timing sequence such that on movementof the valve spool from its center position in either direction itsequentially closes any connection between work chamber and exhaustchambers, opens a work chamber to the pressure chamber and finally opensthe other work chamber to exhaust.
 7. A fluid valve structure as claimedin claim 5 having a signal chamber between one work chamber and thepressure chamber intersecting the passage between the work chambers, apair of pilot pistons in said passage between the work chambers, eachhaving a pressure surface open to said signal chamber whereby when thespool is moved to connect one of the work chambers to an adjacent tankchamber the pressure chamber is connected to the opposite work chamberand the two pilot pistons move together to open the load holding checkconnecting the said one work chamber to the adjacent tank chamber.
 8. Afluid valve structure as claimed in claim 10 having a detented positionon said spool in which the spool connects both work chambers with anadjacent tank chamber, means for holding said spool in said detentposition, whereby when the spool is moved to said detent position, thepressure chamber is connected to said signal chamber and the two pilotpistons move apart to open both load holding checks connecting each workchamber to the adjacent tank chambers.
 9. A fluid valve structure asclaimed in claim 4 wherein the valve grooves are arranged for timingsequence such that on movement of the valve spool from its centerposition in either direction it sequentially closes any connectionbetween work chamber and exhaust chambers, opens a work chamber to thepressure chamber and finally opens the other work chamber to exhaust.10. A fluid valve structure as claimed in claim 4 wherein each workchamber is provided with a load holding check and a passage connectssaid work chambers carrying a pilot piston operative on pressure fromone or the other of the work chambers to move the pilot piston to openthe load holding check in the other work chamber, slots, separate fromthe flow slots to the work chambers, to vent the work chambers to tankwhen the spool is in its center position, said slots to close the workchambers before either flow slot is opened to pressure and finally opensthe opposite work port to tank as the spool is moved from its centerposition.
 11. A fluid valve structure as claimed in claim 1 having adetented position on said spool in which the spool connected both workchambers with an adjacent tank chamber and means for holding said spoolin said detent position.
 12. A fluid valve structure as claimed in claim11 wherein the means for holding said spool in the detent position is atleast one resiliently mounted ball out of contact with any movingfrictional force and a groove with an entering land over which the ballpasses to enter the groove.
 13. A fluid valve structure comprising afirst inlet section separately connected to a source of pressure fluidand to a reservoir, a second inlet section, a plurality of side by sidevalve sections between said first inlet and second inlet sections eachhaving a housing with at least one inlet chamber, a work chamber and atank chamber intersected by a passage open at opposite ends to a controlchamber and a tank chamber at a common pressure, a valve spool havingboth ends in said chamber at a common pressure and being movable in saidpassage, said spool having spaced grooves adapted in one position toconnect said work chamber to the inlet chamber and in a second positionto connect the work chamber with a tank position, lever means in saidcontrol chamber engaging one end of the valve spool, said lever beingrotatable about a shaft whose axis is transverse to and spaced from theaxis of spool valve, seals and bearings in said housing through whichboth ends of said shaft pass to the outside of the valve housing, handlemeans external of the housing acting on the shaft means to rotate thelever whereby the valve spool moves axially in the passage, said shaft,lever and valve spool being fully enclosed within the valve housing inall operative positions and wherein the valve grooves are arranged fortiming sequence such that on movement of the valve spool from its centerposition in either direction it sequentially closes any connectionbetween work chamber and exhaust chambers, opens a work chamber to thepressure chamber and finally opens the other work chamber to exhaust.14. A fluid valve structure as claimed in claim 13 wherein a parallelpressure passage is provided from the first inlet section to a secondinlet section such that pressure fluid is provided at two points in thevalve bank to minimize pressure drop to sections remote from the firstinlet.
 15. A fluid valve structure as claimed in claim 14 wherein thefirst inlet section contains a pressure actuated priority valve thatgives fluid flow to a primary function priority over fluid flow tosecond functions.
 16. A fluid valve structure as claimed in claim 13wherein the shaft and handle means are axially located by the engagementof the lever means in the spool.
 17. A fluid valve structure as claimedin claim 13 wherein each spool has a centering mechanism forautomatically centering the spool when the lever means is not actuated.18. A fluid valve structure as claimed in one of claims 13, 16 or 17wherein each work chamber is provided with a load holding check and apassage connecting said work chambers carrying a pilot piston operativeon pressure from one work chamber to move the pilot piston to open theload check in the other work chamber.
 19. A fluid valve structure asclaimed in claim 18 having a signal chamber between one work chamber andthe pressure chamber intersecting the passage between the work chambers,a pair of pilot pistons in said passage between the work chambers, eachhaving a pressure surface open to said signal chamber whereby when thespool is moved to connect one of the work chambers to an adjacent tankchamber the pressure chamber is connected to the opposite work chamberand the two pilot pistons move together to open the load holding checkconnecting the said one work chamber to the adjacent tank chamber.
 20. Afluid valve structure as claimed in claim 19 having a detented positionon said spool in which the spool connects both work chambers with anadjacent tank chamber, means for holding said spool in said detentposition, whereby when the spool is moved to said detent position, thepressure chamber is connected to said signal chamber and the two pilotpistons move apart to open both load holding checks connecting each workchamber to the adjacent tank chambers.
 21. A fluid valve structure asclaimed in claim 18 having a signal chamber between one work chamber andthe pressure chamber intersecting the passage between the work chambers,a pair of pilot pistons in said passage between the work chambers, eachhaving a pressure surface open to said signal chamber whreby when thespool is moved to connect one of the work chambers to an adjacent tankchamber the pressure chamber is connected to the opposite work chamberand the two pilot pistons move together to open the load holding checkconnecting the said one work chamber to the adjacent tank chamber.
 22. Afluid valve structure as claimed in claim 21 having a detented positionon said spool in which the spool connects both work chambers with anadjacent tank chamber, means for holding said spool in said detentposition, whereby when the spool is moved to said detent position, thepressure chamber is connected to said signal chamber and the two pilotpistons move apart to open both load holding checks connecting each workchamber to the adjacent tank chambers.
 23. A fluid valve structure asclaimed in claim 13 having a detented position on said spool in whichthe spool connected both work chambers with an adjacent tank chamber andmeans for holding said spool in said detent position.
 24. A fluid valvestructure as claimed in claim 23 wherein the means for holding saidspool in the detent position is at least one resiliently mounted ballout of contact with any moving frictional force and a groove with anentering land over which the ball passes to enter the groove.
 25. Afluid valve structure comprising a first inlet section separatelyconnected to a source of pressure fluid and to a reservoir, a secondinlet section, a plurality of side by side valve sections between saidfirst inlet and second inlet sections each having a housing with atleast one inlet chamber, a work chamber and a tank chamber intersectedby a passage open at opposite ends to a control chamber and a tankchamber at a common pressure, a valve spool having both ends in saidchamber at a common pressure and being movable in said passsage, saidspool having spaced grooves adapted in one position to connect said workchamber to the inlet chamber and in a second position to connect thework chamber with a tank position, lever means in said control chamberengaging one end of the valve spool, said lever being rotatable about ashaft whose axis is transverse to and spaced from the axis of spoolvalve, seals and bearings in said housing through wihch both ends ofsaid shaft pass to the outside of the valve housing, handle meansexternal of the housing acting on the shaft means to rotate the leverwhereby the valve spool moves axially in the passage, said shaft, leverand valve spool being fully enclosed within the valve housing in alloperative positions and wherein each work chamber is provided with aload holding check and a passage connects said work chambers carrying apilot piston operative on pressure from one or the other of the workchambers to move the pilot piston to open the load holding check in theother work chamber, slots, separate from the flow slots to the workchambers, to vent the work chambers to tank when the spool is in itscenter position, said slots to close the work chambers before eitherflow slot is opened to pressure and finally opens the opposite work portto tank as the pool is moved from its center position.
 26. A fluid valvestructure as claimed in claim 25 having a signal chamber between onework chamber and the pressure chamber intersecting the passage betweenthe work chambers, a pair of pilot pistons in said passage between thework chambers, each having a pressure surface open to said signalchamber whereby when the spool is moved to connect the work chambers toadjacent tank chambers the pressure chamber is connected to the signalchamber and the two pilot pistons move apart to open the load holdingchecks.
 27. A fluid valve structure as claimed in claim 26 wherein thespool position to provide pressure to the signal chamber is a fourthfloat position beyond the normal metering stroke of the spool.
 28. Afluid valve structure as claimed in claim 27 having a spool detentingmeans to hold the spool in the fourth float position.
 29. A fluidactuated valve as claimed in claim 28 wherein a parallel pressurepassage is provided from the first inlet section to a second inletsection such that pressure fluid is provided at two points in the valvebank to minimize pressure drop to sections remote from the first inlet.30. A fluid valve structure as claimed in claim 29 wherein the firstinlet section contains a pressure actuated priority valve that givesfluid flow to a primary function priority over fluid flow to secondfunctions.
 31. A fluid valve structure as claimed in claim 28 whereinthe means for holding said spool in the detent position is such that thedetent balls or plungers are spring loaded but are not forced intocontact with any port of the non moving wall and a groove with anentering land which the balls or plungers must contact and forced overin order to enter the groove.
 32. A fluid actuated valve as claimed inclaim 31 wherein a parallel pressure passage is provided from the firstinlet section to a second inlet section such that pressure fluid isprovided at two points in the valve bank to minimize pressure drop tosections remote from the first inlet.
 33. A fluid valve structure asclaimed in claim 32 wherein the first inlet section contains a pressureactuated priority valve that gives fluid flow to a primary functionpriority over fluid flow to second functions.
 34. A fluid actuated valveas claimed in claim 27 wherein a parallel pressure passage is providedfrom the first inlet section to a second inlet section such thatpressure fluid is provided at two points in the valve bank to minimizepressure drop to sections remote from the first inlet.
 35. A fluid valvestructure as claimed in claim 34 wherein the first inlet sectioncontains a pressure actuated priority valve that gives fluid flow to aprimary function priority over fluid flow to second functions.
 36. Afluid actuated valve as claimed in claim 26 wherein a parallel pressurepassage is provided from the first inlet section to a second inletsection such that pressure fluid is provided at two points in the valvebank to minimize pressure drop to sections remote from the first inlet.37. A fluid valve structure as claimed in claim 36 wherein the firstinlet section contains a pressure actuated priority valve that givesfluid flow to a primary function priority over fluid flow to secondfunctions.
 38. A fluid actuated valve as claimed in claim 25 wherein aparallel pressure passage is provided from the first inlet section to asecond inlet section such that pressure fluid is provided at two pointsin the valve bank to minimize pressure drop to sections remote from thefirst inlet.
 39. A fluid valve structure as claimed in claim 38 whereinthe first inlet section contains a pressure actuated priority valve thatgives fluid flow to a primary function priority over fluid flow tosecond functions.
 40. A fluid valve structure as claimed in claim 25wherein the shaft and handle means are axially located by the engagementof the lever means in the spool.
 41. A fluid valve structure as claimedin claim 25 wherein each spool has a centering mechanism forautomatically centering the spool when the lever means is not actuated.42. A fluid valve structure as claimed in one of claims 25, 40, or 41wherein each work chamber is provided with a load holding check and apassage connecting said work chambers carrying a pilot piston operativeon pressure from one work chamber to move the pilot piston to open theload check in the other work chamber.
 43. A fluid valve structure asclaimed in claim 25 having a detented position on said spool in whichthe spool connected both work chambers with an adjacent tank chamber andmeans for holding said spool in said detent position.
 44. A fluid valvestructure as claimed in claim 43 wherein the means for holding saidspool in the detent position is at least one resiliently mounted ballout of contact with any moving frictional force and a groove with anentering land over which the ball passes to enter the groove.